kexec: x86: Include pref_address when looking for a memory hole
When the kernel is built relocatable, the starting address can be
anything above 1Mb on x86. However, the startup_*() entries consider
that the minumum address for the kernel for the decompression has to
be at least LOAD_PHYSICAL_ADDR which is turn the value that is provided
as pref_address in boot protocol. The boot protocol itself says:
This field, if nonzero, represents a preferred load address for the
kernel. A relocating bootloader should attempt to load at this
address if possible.
Besides that the code in the kernel (arch/x86/kernel/kexec-bzimage64.c)
has these lines (in bzImage64_load() function):
if (header->pref_address < MIN_KERNEL_LOAD_ADDR)
kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
else
kbuf.buf_min = header->pref_address;
All that said, do the same in kexec tools. Without this patch
the relocatable kernel may end up in the memory hole that is
not enough for in-place decompression and Bad Things will happen
as it's proven on Intel Merrifield, that has a reserved memory
block starting at 64Mb.
Note, it doesn't mean that kernel has no issues itself in this particular
stage, but at least we may work around some corner cases for kexec.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Simon Horman <horms@kernel.org>
2 files changed
